Efficacy of Co-administration of an NSAID With a Dopamine Agonist In Healthy Subjects

Sponsor

Northwestern University (Other)

Overall Status

Withdrawn

CT.gov ID

NCT02116790

Collaborator

National Institute of Dental and Craniofacial Research (NIDCR) (NIH), National Institutes of Health (NIH) (NIH)

Enrollment

Arms

Duration (Months)

Study Details

Study Description

Brief Summary

Findings from the investigator's lab and others' show the involvement of the brain's mesolimbic circuitry in pain perception and evaluation, as well as during the transition from acute to chronic pain states in both humans and animals. Dopamine (DA) is one of the main neurotransmitters in this circuitry, and it is possible it could have an intimate role in pain processing, chronicity, and related anatomical and functional neuroplasticity. In this study, the investigators first need to know if the combination of l-dopa and Naproxen is safe and efficacious in humans with acute pain, and if so, at what doses. For the present study, healthy pain-free participants will be injected with a small bolus of capsaicin subcutaneously to induce acute cutaneous inflammatory pain. Capsaicin is ideal for this study because it causes a characteristic inflammatory response that is almost always accompanied with pain, has a well-validated dose-response curve, and has effects that will go away completely in a few hours after administration, causing no permanent damage to study subjects. Effects of capsaicin will be measured by changes (decreases) from baseline in thermal and tactile thresholds, as well as by verbally reported cutaneous pain levels (on a scale from 0-10). Participants will also be given study medication in the form of a placebo, one drug, or a combination of drugs before capsaicin injection to allow for any analgesic effects to peak before pain onset. For those receiving active medication, they will either receive Naproxen with placebo or the combination of naproxen and l-dopa (the latter of which will be in one of two different doses). This will allow the investigators to investigate (1) whether co-administration of naproxen and l-dopa has analgesic effects in low levels of acute pain in humans, (2) if this combination is pain-alleviating, whether it is equally as or more efficacious than naproxen, which is the clinical standard of treatment, and finally (3) what dose provides the most analgesia.

Condition or Disease	Intervention/Treatment	Phase
Acute Pain	Drug: Naproxen Drug: Sinemet Drug: Sinemet Drug: Placebo	Phase 2

Study Design

Study Type:

Interventional

Actual Enrollment :

0 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Triple (Participant, Investigator, Outcomes Assessor)

Primary Purpose:

Treatment

Official Title:

Study of the Efficacy of Co-administration of an NSAID With a Dopamine Agonist in the Alleviation of Acute Cutaneous Inflammatory Pain in Healthy Subjects

Study Start Date :

May 1, 2014

Anticipated Primary Completion Date :

Jan 1, 2015

Anticipated Study Completion Date :

Jan 1, 2015

Arms and Interventions

Arm	Intervention/Treatment
Placebo Comparator: Control Group 10 participants will be given two pills: both will be placebos	Drug: Placebo Subjects will take two placebos. Other Names: Sugar Pill
Active Comparator: Standard Treatment / Positive Control Group 10 participants will be given two pills: both will be Naproxen (each pill = 250mg, total dose = 500mg)	Drug: Naproxen Subjects will take one 250mg Naproxen capsule Other Names: Aleve Anaprox Antalgin Apranax Feminax Ultra Flanax Inza Midol Extended Relief Nalgesin Naposin Naprelan Naprogesic Naprosyn Narocin Proxen Soproxen Synflex Xenobid
Active Comparator: Experimental Group #1 10 participants will be given two pills: one will be Naproxen (250 mg) and the other will be of Sinemet (carbidopa/levodopa 12.5mg/50mg)	Drug: Naproxen Subjects will take one 250mg Naproxen capsule Other Names: Aleve Anaprox Antalgin Apranax Feminax Ultra Flanax Inza Midol Extended Relief Nalgesin Naposin Naprelan Naprogesic Naprosyn Narocin Proxen Soproxen Synflex Xenobid Drug: Sinemet Subjects will take one 12.5mg/50mg Sinemet. Other Names: Carbidopa/levodopa Levocarb Pharmacopa Atamet Apo-Levocarb Co-careldopa
Active Comparator: Experimental Group #2 10 participants will be given two pills: one will be Naproxen (250 mg) and the other will be of Sinemet (carbidopa/levodopa 25mg/100mg )	Drug: Naproxen Subjects will take one 250mg Naproxen capsule Other Names: Aleve Anaprox Antalgin Apranax Feminax Ultra Flanax Inza Midol Extended Relief Nalgesin Naposin Naprelan Naprogesic Naprosyn Narocin Proxen Soproxen Synflex Xenobid Drug: Sinemet Subjects will take one 25mg/100mg Sinemet. Other Names: Carbidopa/levodopa Levocarb Pharmacopa Atamet Apo-Levocarb Co-careldopa

Outcome Measures

Primary Outcome Measures

VAS pain scale [1 Day]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Must be currently healthy and have none of the exclusion criteria listed below.
Must be at least 18 years of age.
Must be able to communicate (speak and write) in English.
Must demonstrate that they understand what the study entails and requires of them.
Must be able to dedicate the amount of time (~3 hours) to participate in the study.

Exclusion Criteria:

History of chronic pain of any kind
Have a current episode of acute pain of any kind (including stomach ache, headache, muscle ache, etc)
History of psychiatric illness or brain injury
History of substance abuse
History of motor impairments
History of another chronic disease (such as heart disease, celiac's, bronchial asthma, etc)
Have a diagnosis of narrow-angle glaucoma
History or presence of high blood pressure
History or presence of melanoma cancer
Currently on a high-protein diet
Women who are pregnant, trying to get pregnant, or breastfeeding
Known or suspected allergies to capsaicin, peppers, levodopa, carbidopa, naproxen, NSAIDs, rubbing alcohol (in the medical wipes), or lidocaine
History or presence of dermatological disorder, including contact dermatitis and a history of skin allergies in general
Presence of a skin lesion in the areas to be tested